The Human Malaria Parasite Pfs47 Gene Mediates Evasion of the Mosquito Immune System

Friday, November 08, 2013 — Poster Session III
10:00 a.m. – 12:00 p.m.	FAES Academic Center (Upper-Level Terrace)	NIAID	MICROBIO-7

Authors

A. Molina-Cruz
L.S. Garver
A. Alabaster
L. Bangiolo
A. Haile
J. Winikor
C. Ortega
B.C.L van Schaijk
R.W. Sauerwein
E. Taylor-Salmon
C. Barillas-Mury

Abstract

Malaria is transmitted by Anopheles mosquitoes causing annually 219 million cases and 660,000 mortalities. Anopheles gambiae efficiently transmits the malaria parasite Plasmodium falciparum in Africa. Some Plasmodium falciparum lines are able to infect a genetically selected malaria refractory A. gambiae strain by evading its immune system. A Quantitative Trait Loci (QTL) mapping was carried out to identify the P. falciparum gene(s) that allow evasion of the A. gambiae immune system. The gene mapping was done in a cross between P. falciparum GB4 that successfully infects and the 7G8 line that is eliminated by melanotic encapsulation. QTL analysis identified one main significant locus in chromosome 13 associated with the phenotype, this locus was confirmed independently by linkage group selection. Based on the expression differences and sequence polymorphisms, candidate genes were selected for detailed genetic analysis. Pfs47, a member of the 6-cys protein family, was identified as the main gene mediating evasion of the A. gambiae immune system. Pfs47 is expressed in the female gametocyte and was found to remain in the surface of the ookinete. Pfs47 may be important to understand adaptation of the parasite to different Anopheline mosquitos around the world, and could be a target for transmission blocking strategies.